KR20210032148A - Apparatus and method for controlling synchronous generator having initial reactive power adjustment function - Google Patents

Abstract

The present invention relates to a synchronous generator control device having an initial input reactive power adjustment function and a method thereof. According to an embodiment of the present invention, the synchronous generator control device having an initial input reactive power adjustment function comprises: a reference signal adjusting unit adjusting a reference signal so that a synchronous generator voltage and a grid voltage match; and a reactive power adjusting unit calculating and providing a reference signal variation for adjusting a terminal voltage of the synchronous generator in addition to the reference signal so that a synchronous generator can adjust reactive power at the initial grid feed-in.

Description

Synchronous generator control device with initial input reactive power adjustment function and its method {APPARATUS AND METHOD FOR CONTROLLING SYNCHRONOUS GENERATOR HAVING INITIAL REACTIVE POWER ADJUSTMENT FUNCTION}

The present invention relates to an apparatus and method for controlling a synchronous generator having an initial input reactive power adjustment function, and more particularly, to adjust a terminal voltage of a synchronous generator according to an initial value of reactive power set by a power plant manager at the time of initial system feed-in. As a result, the present invention relates to a synchronous generator control apparatus having an initial input reactive power adjustment function and a method thereof for stably supplying reactive power to a power system to improve transient stability of the power system.

Synchronous generators (or synchronous machines) must be fed in by matching the voltage level, voltage phase, and frequency of the power system in order to feed into the power system. In this way, a synchronous feed-in device for synchronous feed-in (or grid feed-in, grid feed-in, synchronous feed-in) is required for the power system feed-in operation by driving the synchronous generator.

In general, the synchronous feed-in device is installed independently, and before the grid feed-in, a command to control terminal voltage to a generator exciter and a command to control speed and phase to a governor of a turbine is given.

However, if the synchronous feed-in device operates the grid-connected circuit breaker without matching the voltage level, voltage phase, and frequency of the power system with the power system, it damages the peripheral voltage, peripheral electric equipment, and turbine facilities at the output stage of the synchronous generator. In addition, it gives a great impact to the power system, causing a great disturbance to the generators running in parallel in the nearby power system.

1 is a diagram showing a connection between a general synchronous feed-in device and an external controller.

If the voltage level of the synchronizer and the power system is not matched and the synchronizer is operated in parallel with the power system, a large ineffective cross-current flows through the generator and the synchronizer may be burned.

In addition, when the synchronizer and the power system are operated in parallel without matching the voltage phases of the synchronizer and the power system, an electrical collision such as a temporary short circuit occurs due to a large voltage difference between the two systems, causing damage to the related devices and improving the stability of the power system. It will have a profound effect on dropping.

Referring to FIG. 1, the voltage level of the synchronizer is in charge of adjusting the exciter, and the voltage phase and frequency are adjusted by a governing system that controls the speed of the turbine rotating the synchronizer.

In addition, the synchronous feed-in device detects the voltage level and frequency signals of the power system and the synchronizer, and after undergoing a signal processing calculation process, it detects the difference in voltage magnitude, voltage phase difference, and phase angle signal between the two systems, and these values are within a set reference value. When it comes in, it generates a command signal to synchronously close the grid-connected circuit breaker to operate the synchronous machine in grid-parallel.

And, when the voltage level, frequency level, and phase angle of the synchronous machine to be fed in are out of the range of the parallel input condition, the synchronous feed-in device generates an increase/decrease command signal to correct the target value of the exciter and the governing system, and this It modifies the target value and sends a command signal to match the constantly changing power system signal.

However, the power plant manager needs to pay attention to the stable supply of reactive power and active power during the initial system feed-in process of the synchronous generator.

In other words, the synchronous feed-in device becomes a condition for closing the circuit breaker when the error between the synchronous generator voltage and the grid voltage is within a certain range. However, in this case, since the amount of reactive power injected varies, the power plant manager's attention is very needed.

Therefore, in some cases, the power plant manager is often caused to rapidly increase the voltage due to excessive fast-paced operation at the initial stage of system feed-in.

Accordingly, there is a need to provide a method for improving the transient stability of the power system by stably supplying reactive power by adjusting the generator voltage according to the initial value of reactive power set by the power plant manager during system feed-in.

Korean Registered Patent Publication No. 10-1063945 (registered in 2011.09.02)

An object of the present invention is to stably supply reactive power to the power system by adjusting the terminal voltage of the synchronous generator according to the initial value of reactive power set by the power plant manager during the initial system feed-in, thereby improving the transient stability of the power system. It is to provide a synchronous generator control apparatus and method having an initial input reactive power adjustment function.

A synchronous generator control apparatus having an initial input reactive power adjustment function according to an embodiment of the present invention includes: a reference signal adjustment unit for adjusting a reference signal so that the synchronous generator voltage and the system voltage match; And a reactive power adjusting unit for calculating and providing a variation of a reference signal for adjusting a terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during the initial system feed-in.

The reactive power adjusting unit may include a reactive power calculating unit for checking a reactive power change and a terminal voltage change using a synchronous generator voltage and current; An impedance calculating unit for calculating a system impedance using the reactive power change and the terminal voltage change; And a reference signal variation calculation unit for calculating a reference signal variation using the system impedance and an initial value of reactive power set by the power plant manager.

The change in reactive power is calculated as a difference between the first reactive power and the second reactive power, the first reactive power is checked when the synchronous generated voltage and the grid voltage match, and the second reactive power is initially It may be checked when the voltage increase is reflected in the reference signal during system feed-in.

The terminal voltage variation is calculated as a difference between a first terminal voltage and a second terminal voltage, the first terminal voltage is a synchronous generator voltage when the first reactive power is the first reactive power, and the second terminal voltage is the second reactive power When is, it may be a synchronous generator voltage.

The variation of the terminal voltage may correspond to the increase of the voltage.

(여기서, Xe는 계통 임피던스, V1는 제1 단자전압, V2는 제2 단자전압, Q1은 제1 무효전력, Q2는 제2 무효전력)로 계산되는 것일 수 있다.The system impedance is Equation

(Wherein, Xe is a system impedance, V1 is a first terminal voltage, V2 is a second terminal voltage, Q1 is a first reactive power, and Q2 is a second reactive power).

(여기서, △Vsref는 기준신호 변동분, Xe는 계통 임피던스, Qref는 무효전력 초기값)로 계산되는 것일 수 있다.The variation of the reference signal is Equation

(Here, ΔVsref is a reference signal variation, Xe is a system impedance, and Qref is an initial value of reactive power).

The reference signal fluctuation calculation unit may be configured to calculate the reference signal fluctuation by applying a current value of reactive power of another synchronous generator operating in parallel in the vicinity of the reactive power instead of the initial value of the reactive power.

The system impedance may be expressed as a sum of the impedance of the peripheral voltage and the impedance of the connection line when the rear end of the grid-connected circuit breaker is represented by equivalent modeling.

According to an embodiment, a speed adjusting unit for transmitting a speed control command to a governor so that the voltage frequency and phase of the synchronous generator voltage and the grid voltage coincide with each other; may be further included.

The reactive power adjusting unit may be installed in an exciter or a synchronous feed-in device.

In addition, a synchronous generator control method having an initial input reactive power adjustment function according to an embodiment of the present invention includes: adjusting a reference signal so that the synchronous generator voltage and the grid voltage match; And calculating and providing a variation of a reference signal for adjusting a terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during initial system feed-in.

The providing may include checking a change in reactive power and a change in terminal voltage using a synchronous generator voltage and current; Calculating a system impedance using the change in reactive power and the change in terminal voltage; And calculating a variation of a reference signal using the system impedance and an initial value of reactive power set by the power plant manager.

The step of calculating the variation of the reference signal may include calculating the variation of the reference signal by applying a current value of reactive power of another synchronous generator operating in parallel in the vicinity instead of the initial value of the reactive power.

In addition, an apparatus for controlling a synchronous generator according to another embodiment of the present invention, comprising: at least one processor; And a memory for storing computer-readable instructions, wherein the instructions, when executed by the at least one processor, cause the synchronous generator control device to adjust the reference signal so that the synchronous generator voltage and the grid voltage match. In addition, in addition to the reference signal, a variation of a reference signal for adjusting the terminal voltage of the synchronous generator may be calculated and provided so that the synchronous generator can adjust the reactive power at the time of initial system feed-in.

The present invention adjusts the terminal voltage of the synchronous generator according to the initial value of reactive power set by the power plant manager during the initial system feed-in, thereby stably supplying reactive power to the power system, thereby improving the transient stability of the power system.

In addition, according to the present invention, a space for installing as an independent device and a management cost can be reduced by integrating a synchronous feed-in device to an exciter installed in each of the power plants.

In addition, the present invention calculates the grid impedance by increasing the synchronous generator voltage after the first grid feed-in after the power plant is built, and the grid impedance is already calculated when the grid is synchronously applied again after a grid disorder, so the reactive power set by the power plant manager The power plant can be operated stably by adjusting the synchronous generator voltage based on the initial value.

In addition, in the present invention, when a plurality of synchronous generators are operating, the synchronous generators that are additionally system-integrated are operated in parallel in the surroundings by applying the current reactive power values of other synchronous generators operating in parallel instead of the initial reactive power values. It can operate stably with other synchronous generators.

In addition, the present invention can be simply applied without changing the structure of the current synchronous bottling device and the exciter by implementing the synchronous bottling device and the exciter in an independent form rather than an integrated form.

1 is a diagram showing a connection between a general synchronous feed-in device and an external controller;
2 is a view showing a synchronous generator control apparatus having an initial input reactive power adjustment function according to an embodiment of the present invention;
3 is a diagram illustrating a detailed configuration of the synchronous generator control device of FIG. 2;
4 is a diagram showing an impedance disconnection between a synchronous generator and an external device;
5 is a graph explaining the results of an operation test for calculating the system impedance;
6 is a diagram showing a method for controlling a synchronous generator having an initial input reactive power adjustment function according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the following description and the accompanying drawings, detailed descriptions of known functions or configurations that may obscure the subject matter of the present invention will be omitted. In addition, it should be noted that the same components are denoted by the same reference numerals as much as possible throughout the drawings.

The terms or words used in the present specification and claims described below should not be construed as being limited to their usual or dictionary meanings, and the inventors are appropriately defined as terms for describing their own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention. It should be understood that there may be equivalents and variations.

In the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size. The present invention is not limited by the relative size or spacing drawn in the accompanying drawings.

When a part of the specification is said to "include" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary. In addition, when a part is said to be "connected" with another part, this includes not only the case of being "directly connected", but also the case of being "electrically connected" with another element interposed therebetween.

Singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and one or more other features, numbers, or steps. It is to be understood that it does not preclude the possibility of the presence or addition of, operations, components, parts, or combinations thereof.

In addition, the term "unit" used in the specification refers to a hardware component such as software, FPGA, or ASIC, and "unit" performs certain roles. However, "unit" is not meant to be limited to software or hardware. The “unit” may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors. Thus, as an example, "unit" refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays and variables. The functions provided within the components and "units" may be combined into a smaller number of components and "units" or may be further separated into additional components and "units".

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a view showing a synchronous generator control apparatus having an initial input reactive power adjustment function according to an embodiment of the present invention.

As shown in FIG. 2, a synchronous generator control device having an initial input reactive power adjustment function according to an embodiment of the present invention (hereinafter referred to as a synchronous generator control device 100) controls the terminal voltage of the synchronous generator. By incorporating and integrating all functions of the synchronous bottling device into the exciter in charge, it can be implemented in the form of a'synchronized bottling device built-in exciter'. That is, the synchronous generator control device 100 may be implemented in a form included in an exciter.

In this case, since the exciter originally receives the generator voltage as a feedback signal, if it receives an additional system voltage, it can sufficiently perform the function of the synchronous and merger device. This is possible because the signal processing performance of the exciter is improved.

Thus, the synchronous generator control device 100 integrates a synchronous feed-in device into an exciter installed in each of the power plants, thereby reducing a space for installation as an independent device and a management cost.

In FIG. 2, the synchronous generator control device 100 needs a synchronous generator voltage and a grid voltage required for calculating a synchronous input control signal in order to function as a synchronous feed-in device.

That is, in the synchronous generator control device 100, the voltage signal Vg and the frequency signal of the synchronous generator G are input through the first voltage transformer 20 disposed on the generator side based on the grid-connected circuit breaker 10. , The current signal (Ig) of the synchronous generator (G) is input through the current transformer (30), and the voltage of the power system through the second voltage transformer (40) disposed on the grid power side based on the grid-connected circuit breaker (10). The signal Vt and the frequency signal are input.

The synchronous generator control device 100 may function as a synchronous feed-in device.

First, the synchronous generator control device 100 compares the frequency (phase) of the synchronous generator G and the frequency (phase) of the power system to control the speed of the governor.

In addition, the synchronous generator control device 100 compares the detection signal between the synchronous generator G and the power system and transmits a breaker input command signal to the grid-connected circuit breaker 10 when it comes within a predetermined reference value. At this time, the synchronous generator control device 100 may check the open/close state of the grid-connected circuit breaker 10.

In addition, the synchronous generator control device 100 may perform an exciter control function.

At this time, the synchronous generator control device 100 supplies DC power to the generator field winding C to maintain or adjust the generator output terminal voltage constant. Here, a stationary exciter control function including a thyristor rectifier 50 that supplies AC power to the generator field winding C as DC power is implemented.

In particular, the synchronous generator control device 100 adjusts the terminal voltage of the synchronous generator G based on the initial value of reactive power set by the power plant manager when feeding the system in which the input condition of the grid-connected circuit breaker 10 is satisfied, It enables the synchronous generator to be stably fed into the power system and operated without additional work from the power plant manager.

Here, reactive power is determined by the difference between the synchronous generator voltage and the grid voltage when the synchronous generator is fed into the grid. In order to calculate reactive power, the system impedance must be checked. However, it is difficult to calculate the system impedance through simulation because numerous generators and system constants are complexly connected.

Therefore, in the embodiment of the present invention, the grid impedance was calculated by increasing the synchronous generator voltage after the first grid feed after the power plant was constructed. When the system is synchronously powered again after a grid disorder, the system impedance has already been calculated, so the power plant can be operated stably by adjusting the synchronous generator voltage based on the initial reactive power value set by the power plant manager.

Hereinafter, a detailed configuration of the synchronous generator control apparatus 100 will be described in detail with reference to FIG. 3.

3 is a diagram illustrating a detailed configuration of the synchronous generator control device of FIG. 2.

Referring to FIG. 3, the synchronous generator control apparatus 100 includes a reference signal adjustment unit 110, a reactive power adjustment unit 120, and a speed adjustment unit 130.

First, the reference signal adjustment unit 110 is in charge of an exciter control function in charge of adjusting the terminal voltage of the synchronous generator (G). That is, the reference signal adjustment unit 110 adjusts the reference signal Vref of the synchronous generator G provided to the PID controller 60 so that the voltage levels of the synchronous generator voltage Vg and the system voltage Vt match. At this time, the reference signal adjusting unit 110 generates a command to increase or decrease the reference signal Vref so that |Vg-Vt|=0. Here, the reference signal Vref may reflect the reference signal variation ΔVsref calculated by the reactive power adjusting unit 120.

Next, the reactive power adjustment unit 120 calculates and provides a reference signal variation (Vsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal (Vref) so that the reactive power can be adjusted when the synchronous generator is initially fed into the system. do. Here, the reference signal variation Vsref reflects the reactive power initial value Qref set by the power plant manager.

Accordingly, the synchronous generator (G) adjusts the terminal voltage according to the reactive power initial value (Qref) set by the power plant manager at the time of initial system feed-in, thereby stably supplying reactive power to the power system, resulting in transient stability of the power system. Will improve.

In other words, the synchronous generator G is capable of outputting the reactive power reflecting the reactive power initial value Qref at the time of initial system feed-in.

Specifically, the reactive power adjusting unit 120 includes a reactive power calculating unit 121, an impedance calculating unit 122, and a reference signal variation calculating unit 123.

First, the reactive power calculator 121 calculates reactive power using the synchronous generator voltage (Vg) and current (Ig), but calculates the reactive power change and the terminal voltage change to calculate the system impedance (Xe). Confirm.

At this time, since it is difficult for the reactive power calculation unit 121 to actually calculate the system impedance by simulation, the reactive power change that can automatically calculate the system impedance assuming a situation in which the power plant is constructed and the generator voltage is increased after the initial system feed-in. And check the change in terminal voltage.

Here, the change in reactive power is calculated as the difference (Q1-Q2) between the first reactive power Q1 and the second reactive power Q2, and the change in terminal voltage is the first terminal voltage V1 and the second terminal voltage. It is calculated as the difference (V1-V2) of (V2).

Specifically, each of the first reactive power (Q1) and the first terminal voltage (V1) is'when the power plant is built and the initial system feed-in (that is, when the synchronous generator voltage (Vg) and the system voltage (Vt) match). 'It is confirmed.

The first reactive power Q1 is reactive power when the synchronous generator voltage Vg and the system voltage Vt match. That is, the first reactive power Q1 becomes '0'.

The first terminal voltage V1 is a synchronous generator voltage determined according to a reference signal (ie, a reference signal adjusted to match the synchronous generator voltage and the grid voltage) at the time of initial system feed-in. That is, the first terminal voltage V1 is a synchronous generator voltage when the first reactive power Q1 is used.

In addition, each of the second reactive power Q2 and the second terminal voltage V2 is checked'when the generator voltage rises after feeding into the system'. Here, the voltage increase (ΔV) may be about 4 to 5%.

The second reactive power Q2 is reactive power when the voltage increase ΔV is reflected in the reference signal during the initial system feed-in.

The second terminal voltage V2 is a synchronous generator voltage determined by reflecting the voltage increase ΔV to the reference signal during the initial system feed-in. That is, the second terminal voltage V2 is the synchronous generator voltage when the second reactive power Q2 is used.

Here, since the second terminal voltage V2 is obtained by adding the voltage increase ΔV to the first terminal voltage V1, the terminal voltage changes V1-V2 are equal to the voltage increase ΔV.

As a result, the reactive power calculating unit 121 checks the first reactive power Q1 as '0' and calculates the second reactive power Q2 by reflecting the voltage increase ΔV, thereby calculating the reactive power change Q1. -Q2) can be checked. In addition, the reactive power calculation unit 121 may check the voltage increase ΔV as the terminal voltage change V1-V2.

Next, the impedance calculating unit 122 calculates the system impedance Xe using the reactive power variation Q1-Q2 and the terminal voltage variation V1-V2. That is, since the system impedance Xe is proportional to the change in reactive power according to the change in the terminal voltage, it can be calculated as in Equation 1 below.

Next, the reference signal variation calculation unit 123 calculates the reference signal variation (ΔVsref) using the system impedance Xe and the reactive power initial value Qref set by the power plant manager. That is, the reference signal variation ΔVsref may be calculated as in Equation 2 below by multiplying the system impedance Xe by the initial reactive power value Qref set by the power plant manager.

Here, the reference signal variation (ΔVsref) is added to the reference signal (Vref) of the synchronous generator voltage. Then, the terminal voltage of the synchronous generator G is adjusted by the reference signal Vref+ΔVsref reflecting the reference signal variation ΔVsref. At this time, the synchronous generator G automatically changes reactive power when synchronous feed-in by the reference signal fluctuation (ΔVsref), so that transient stability may be secured at an initial stage.

Additionally, when a plurality of synchronous generators are in operation, the synchronous generator that is additionally fed into the system may apply the'reactive power present value' of other synchronous generators operating in parallel in the surroundings instead of the reactive power initial value (Qref). Then, since the synchronous generator that is additionally fed into the grid can be expected to be fed into the grid by correcting the reactive power in real time, it is possible to stably operate together with other synchronous generators operating in parallel in the surroundings.

Next, the speed adjustment unit 130 is in charge of a governor control function in charge of adjusting the voltage frequency and phase of the synchronous generator G. To this end, the speed adjustment unit 130 calculates the voltage frequency and phase of the synchronous generator G.

The speed adjustment unit 130 transmits a speed control command to the governor so that the voltage frequency and phase of the synchronous generator voltage Vg and the power system voltage Vt are matched.

As described above, the synchronous generator control device 100 may be implemented in the form of a'synchronous bottling device built-in exciter'.

However, the synchronous generator control device 100 may be implemented in a form independent from each other, not in an integrated form with a synchronous feed-in device and an exciter. In this case, the reactive power adjusting unit 120 is installed in the synchronous feed-in device, and a reference signal variation (ΔVsref) is provided to the exciter. Then, the exciter adjusts the synchronous generator (G) and the synchronous generator (G) by using the reference signal in which the variation of the reference signal is reflected. A detailed description of this will be omitted because it can be easily understood by those of ordinary skill in the art.

Meanwhile, the synchronous generator control apparatus 100 may be implemented in a configuration including at least one processor and a memory for storing computer-readable instructions.

That is, each of the reference signal adjusting unit 110, the reactive power adjusting unit 120, and the speed adjusting unit 130 has an initial input reactive power adjusting function according to an embodiment of the present invention when computer-readable instructions stored in the memory are executed by a process. It is possible to perform the synchronous generator control method provided with.

Here, the processor may also be referred to as a controller, a microcontroller, a microprocessor, a microcomputer, or the like. In addition, the processor may be implemented by hardware, firmware, software, or a combination thereof.

In addition, the memory may be a single storage device, or may be a collective term for a plurality of storage elements. Computer-readable instructions stored in the memory may be executable program code or parameters, data, and the like. In addition, the memory may include a random access memory (RAM), or may include a non-volatile memory (NVRAM) such as a magnetic disk storage device or a flash memory.

4 is a diagram showing an impedance disconnection between a synchronous generator and an external device, and FIG. 5 is a graph illustrating an operation test result for calculating a system impedance.

4, the organic electromotive force (E) and the synchronous impedance (Xs) are parts representing the synchronous generator (G) by equivalent modeling, and the peripheral voltage impedance (Xt) and the connection line impedance (Xl) are the grid-connected circuit breaker 10 ) This is the part that shows the latter part and beyond by equivalent modeling.

Here, the system impedance Xe may be expressed as the sum of the peripheral voltage impedance Xt and the connection line impedance Xl. That is, Xe=Xt+Xl.

This impedance corresponds to the device and shows a constant value if the peripheral synchronous generator or line does not change.

Referring to FIG. 5, a 500mW synchronous generator was applied as an operation test object. The specifications of the synchronous generator are rated voltage 22,000V, frequency 60㎐(3600rpm), rated output 612㎹A, field voltage 300V, field current 5,224A, field voltage 0.0546@75℃.

Specifically, the system impedance Xe may be calculated through Equation 1 above.

First, since the terminal voltage change (V1-V2) is the same as the voltage increase (ΔV), if it is increased by 5%, it becomes -0.05. That is, when the first terminal voltage V1 is 1V, the second terminal voltage V2 becomes 1.05V by adding the first terminal voltage and the voltage increase (ΔV). Then, the change in terminal voltage (V1-V2) is -0.05.

Next, the first reactive power Q1 is 0, and the second reactive power Q2 is the reactive power checked when the voltage increase (ΔV) is reflected in the reference signal Vref at the time of initial system feed-in. The second reactive power Q2 is confirmed to be 0.215.

Therefore, the system impedance Xe is calculated as 0.232pu.

이다.In other words,

to be.

Then, the reference signal variation (ΔVsref) may be calculated through Equation 2 above. Here, the initial reactive power value Qref may be, for example, 0.2pu.

Therefore, the variation of the reference signal (ΔVsref) is calculated as 0.0464pu.

이다.In other words,

to be.

6 is a diagram showing a method for controlling a synchronous generator having an initial input reactive power adjustment function according to an embodiment of the present invention.

Referring to FIG. 6, the synchronous generator control apparatus 100 adjusts the reference signal Vref of the synchronous generator G so that the synchronous generator voltage Vg and the system voltage Vt match (S201). That is, the synchronous generator control device 100 adjusts the reference signal Vref so that |Vg-Vt|=0.

At this time, the synchronous generator control device 100 checks whether the reactive power Q becomes '0' (S202), and if this is satisfied, the first terminal voltage V1 and the first reactive power Q1 are checked and stored. Do (S203). Here, the first terminal voltage V1 becomes a synchronous generator voltage when the first reactive power Q1 is '0'.

Thereafter, the synchronous generator control device 100 increases the voltage of the reference signal Vref of the synchronous generator G to check and store the second terminal voltage V2 and the second reactive power Q2 (S204, S205). ). Here, the reference signal Vref is increased by 4 to 5%.

Then, the synchronous generator control apparatus 100 calculates the system impedance Xe using the reactive power change Q1-Q2 and the terminal voltage change V1-V2 (S206). Here, the system impedance may be calculated as in Equation 1 above.

Thereafter, the synchronous generator control apparatus 100 calculates and provides the reference signal variation ΔVsref using the system impedance Xe and the reactive power initial value Qref set by the power plant manager (S207). Here, the reference signal variation ΔVsref may be calculated as in Equation 2 above.

Accordingly, the synchronous generator G can adjust the terminal voltage of the synchronous generator G by adding the reference signal variation ΔVsref to the reference signal Vref (S208).

As described above, the synchronous generator control device 100 is a reference signal fluctuation for adjusting the terminal voltage of the synchronous generator G in addition to the reference signal Vref so that the synchronous generator can adjust the reactive power during the initial system feed-in. (△Vsref) is calculated and provided.

The method according to some embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded in the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CDROMs and DVDs, and magnetic-optical media such as floptical disks. And hardware devices specially configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like.

Although the above description has been described with focus on the novel features of the present invention applied to various embodiments, those skilled in the art will have the above-described apparatus and method without departing from the scope of the present invention. It will be appreciated that various deletions, substitutions, and changes are possible in form and detail of the Accordingly, the scope of the present invention is defined by the appended claims rather than by the above description. All modifications within the scope of equivalents of the claims are included in the scope of the present invention.

10; Grid-connected circuit breaker 20; First voltage transformer
30; Current transformer 40; Second voltage transformer
50; Thyristor rectifier 60; PID controller
C; Generator field winding G; Synchronous generator
110; A reference signal adjustment unit 120; Reactive power regulator
121; Reactive power calculation unit 122; Impedance calculation unit
123; A reference signal variation calculation unit 130; Speed adjuster

Claims (21)

A reference signal adjustment unit 110 for adjusting the reference signal Vref so that the synchronous generator voltage Vg and the system voltage Vt match; And
A reactive power adjusting unit 120 for calculating and providing a reference signal variation (ΔVsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power at the time of initial system feed-in;
Synchronous generator control device having an initial input reactive power adjustment function comprising a.
The method of claim 1,
The reactive power adjustment unit,
A reactive power calculating unit 121 for checking a reactive power change and a terminal voltage change using the synchronous generator voltage Vg and the current Ig;
An impedance calculating unit 122 for calculating a system impedance Xe using the reactive power change and the terminal voltage change; And
A reference signal variation calculation unit 123 for calculating a reference signal variation (ΔVsref) using the system impedance and an initial reactive power value (Qref) set by a power plant manager;
Synchronous generator control device having an initial input reactive power adjustment function comprising a.
The method of claim 2,
The change in reactive power is,
It is calculated as the difference between the first reactive power (Q1) and the second reactive power (Q2),
The first reactive power is checked when the synchronous generation voltage and the grid voltage match,
The second reactive power is checked when a voltage increase (ΔV) is reflected in the reference signal during initial system feed-in.
The method of claim 3,
The variation of the terminal voltage is:
It is calculated as the difference between the first terminal voltage V1 and the second terminal voltage V2,
The first terminal voltage is a synchronous generator voltage when the first reactive power is applied,
When the second terminal voltage is the second reactive power, the synchronous generator control device having an initial input reactive power adjustment function that is a synchronous generator voltage.
The method of claim 4,
The terminal voltage fluctuation corresponds to the voltage increase, the synchronous generator control device having an initial input reactive power adjustment function.
The method of claim 4,
The system impedance is,
Equation

(Where Xe is the system impedance, V1 is the first terminal voltage, V2 is the second terminal voltage, Q1 is the first reactive power, and Q2 is the second reactive power). Synchronous generator control device.
The method of claim 2,
The variation of the reference signal is
Equation

(Where, ΔVsref is the reference signal variation, Xe is the system impedance, and Qref is the initial value of reactive power). The synchronous generator control device having an initial input reactive power adjustment function.
The method of claim 7,
The reference signal variation calculation unit,
A synchronous generator control device having an initial input reactive power adjustment function to calculate the variation of the reference signal by applying a current value of reactive power of another synchronous generator operating in parallel in the vicinity of the reactive power instead of the initial value of the reactive power.
The method of claim 2,
The system impedance is,
Synchronous generator control device with an initial input reactive power adjustment function, which is expressed by the sum of the peripheral voltage impedance (Xt) and the interconnection line impedance (Xl) when the rear end of the grid-connected circuit breaker is represented by equivalent modeling.
The method of claim 1,
A speed adjusting unit for transmitting a speed control command to a governor so that the voltage frequency and phase of the synchronous generator voltage and the grid voltage match;
Synchronous generator control device having an initial input reactive power adjustment function further comprising a.
The method of claim 1,
The reactive power adjustment unit,
Synchronous generator control device having an initial input reactive power adjustment function that is installed in an exciter or a synchronous feed-in device.
Adjusting the reference signal (Vref) so that the synchronous generator voltage (Vg) and the system voltage (Vt) match; And
Calculating and providing a reference signal variation (ΔVsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during initial system feed-in;
Synchronous generator control method having an initial input reactive power adjustment function comprising a.
The method of claim 12,
The providing step,
Identifying a change in reactive power and a change in terminal voltage using the synchronous generator voltage (Vg) and current (Ig);
Calculating a system impedance (Xe) using the reactive power change and the terminal voltage change; And
Calculating a reference signal variation (ΔVsref) using the system impedance and an initial reactive power value (Qref) set by a power plant manager;
Synchronous generator control method having an initial input reactive power adjustment function comprising a.
The method of claim 13,
The change in reactive power is,
It is calculated as the difference between the first reactive power (Q1) and the second reactive power (Q2),
The first reactive power is checked when the synchronous generation voltage and the grid voltage match,
The second reactive power is checked when the voltage increase (ΔV) is reflected in the reference signal during the initial system feed-in.
The method of claim 14,
The variation of the terminal voltage is:
It is calculated as the difference between the first terminal voltage V1 and the second terminal voltage V2,
The first terminal voltage is a synchronous generator voltage when the first reactive power is applied,
The second terminal voltage is the synchronous generator voltage when the second reactive power is a synchronous generator control method having an initial input reactive power adjustment function.
The method of claim 15,
The terminal voltage fluctuation corresponds to the voltage increase in the synchronous generator control method having an initial input reactive power adjustment function.
The method of claim 15,
The system impedance is,
Equation

(Where Xe is the system impedance, V1 is the first terminal voltage, V2 is the second terminal voltage, Q1 is the first reactive power, and Q2 is the second reactive power). Synchronous generator control method.
The method of claim 13,
The variation of the reference signal is
Equation

(Where, ΔVsref is the reference signal variation, Xe is the system impedance, and Qref is the initial value of reactive power), which is calculated as a synchronous generator control method having an initial input reactive power adjustment function.
The method of claim 18,
The step of calculating the variation of the reference signal,
A method of controlling a synchronous generator with an initial input reactive power adjusting function, wherein the reference signal variation is calculated by applying a current value of reactive power of another synchronous generator operating in parallel in the surrounding area instead of the initial value of the reactive power.
The method of claim 13,
The system impedance is,
Synchronous generator control method with initial input reactive power adjustment function, which is expressed by the sum of the peripheral voltage impedance (Xt) and the interconnection line impedance (Xl) when the rear end of the grid-connected circuit breaker is represented by equivalent modeling.
As a synchronous generator control device,
At least one processor; And
Including; a memory for storing computer-readable instructions,
The instructions, when executed by the at least one processor, cause the synchronous generator control device,
Adjust the reference signal (Vref) so that the synchronous generator voltage (Vg) and the system voltage (Vt) match,
A synchronous generator control device configured to calculate and provide a reference signal variation (ΔVsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust reactive power during initial system feed-in.

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